Tim sorry about the trucks age itsa 59 just happen to have 2 3x6 pt post laying in yard and harbor freight is near. like the steel wheels as my driveway is asphalt . I think a 4" dia wheel would work. ijust want to be able to move it around and maybe on to a trailer to welder. Anybody have a guestament of the weight of a cab? need it to be strong enough to have the doors on for fiting.